This section provides background information related to the present disclosure which is not necessarily prior art.
Healthcare delivery in today's hospitals is a complex task. A major source of complexity derives from the interdependency and interaction between multiple operations or units in the hospital, e.g. inpatient units, emergency departments (EDs), operating rooms (ORs), central sterilization department (CSD) and intensive care units (ICUs). For example, inefficient boarding in an inpatient unit that results in crowding in the ED is a manifestation of interdependency among operations in a hospital. Boarding is the term used to describe scheduling a patient for a procedure or otherwise entering the patient into the system of a particular unit. Another related source of complexity derives from the interdependency and interaction between various processes and resources required to complete a task within a single operation or unit. For example, in an OR, providing a greater degree of accessibility to surgeons or patients at the expense of utilization or productivity is an example of an interaction among processes or resources within an operation. Thus, it should be apparent that because interaction and interdependence couple the operations and processes in healthcare delivery, there is a need to manage healthcare delivery as a system.
In managing a healthcare delivery system, one must consider the functional requirements of the operations that comprise the system and the design parameters that render the functional requirements mutually exclusive and free from interactions and interdependencies. As interactions and interdependencies of functional requirements are reduced, if not eliminated, the system becomes less complex. A functional requirement may be thought of as a desired objective, while a design parameter may be thought of as how to achieve a functional requirement. In defining a set of functional requirements for a healthcare system, one should ensure to craft a list of functional requirements that is exhaustive and non-frivolous. Defining functional requirements will ensure that the operations are effective and defining design parameters will ensure that operations are efficient.
In the healthcare industry there are many functional requirements. The most common functional requirements in operations and their corresponding metrics are:
1) raise throughput—the number of jobs completed per unit time, the goal is to maximize this metric;
2) reduce length of stay—the length of time a patient stays in the system, the goal is to minimize this metric;
3) efficient use of resources—the level of capacity utilization, the goal is to maximize this metric;
4) reduce wait time—the length of time between the arrival of a job and the commencement of processing the job, the goal is to minimize this metric;
5) deliver service on time—the difference between the time a job is due and the actual time the job is finished, the goal is to minimize this metric; and
6) deliver service reliably—the consistency in delivering a job on time, the goal is to maximize this metric.
The design parameters for the functional requirements described above may include the following process variables:
1) processing time—the length of time to process a job;
2) due date—the date by which a task must be completed;
3) capacity—the amount of resources available, e.g. the amount of available beds in a unit;
4) slack time—time until due date minus processing time; and
5) completion time—the time when a job is actually finished.
As can be seen from the above definitions, two or more functional requirements may depend on the same process variables. For example, both throughput and length of stay are dependent on the processing time of a patient, that is—the amount of time it takes to diagnose and treat a patient. It logically follows that the two functional requirements cannot be independently satisfied by the same process variable. Thus, the two functional requirements, length of stay and throughput are coupled because they involve the same process variable. Similarly, deliver service on time and deliver service reliability are coupled, as the two functional requirements are dependent on the due date variable.
While tools and techniques to optimize functional requirements have been developed, these solutions do not take coupling into account. Instead, they address a specific functional requirement at the expense of other functional requirements. These trade-off schemes, which seek to mitigate the ill effect of the non-optimized functional requirement, result in sub-optimal coupled systems. Thus, there is a strong need for a system or tool to optimize coupled systems in the healthcare delivery industry.